Can anyone find the source code for the chatbot Luna?
You can't find the source code because it doesn't exist. The whole thing was a 2015 kickstarter scam, and now it's a patreon scam. All the tech "demos" are obviously pre-scripted videos.

There was actually a question on Quora about it, in which one of the answerers managed to find, among other things, the question and answer that his fake AI gave in one of the videos.